Merge fiferpg editor into fifengine project?

[LinuxDonald]

Belair have done some work on his fiferpg-editor that it can load and edit fife maps.
What about to add it into the fife project and work together on it?
We could use it as base for the new fife editor and add support that it supports different Project based on fife? https://github.com/fife-rpg/editor

@helios2000 @prock-fife @Beliaar what do you guys think about this?